1. The Prior Art
Dozers, road graders, and agricultural tractors have conventionally used rectangular shaped blades for excavating, pushing and grading earth materials including snow. Many of these blades have been disclosed in patents, and the following are exemplary of the types of patents issued in this class; U.S. Pat. No. 4,464,852 to Rice, U.S. Pat. No. 4,445,577 to Russell D.E. and Russell T.H., U.S. Pat. No. 4,306,625 to Davis, U.S. Pat. No. 4,554,978 to Schneider, U.S. Pat. No. 4,135,583 to Becker, and U.S. Pat. No. 3,853,181 to Yoshizaki.
Multi-blades and articulated blades such as those disclosed by U.S. Pat. No. 4,834,191 to Vecchio, U.S. Pat. No. 4,758,116 to Ezoe, U.S. Pat. No. 4,384,620 to Uchida et al., U.S. Pat. No. 4,270,617 to Cantarella and Cecchi, U.S. Pat. No. 4,099,578 to Stevens, U.S. Pat. No. 4,029,157 to Freese, and U.S. Pat. No. 4,019,587 to Meisel, have also been invented to aid in the excavation, pushing, and grading process for various earth materials. All of the prior art blade inventions, including the multi-blade and articulated blades, use contiguous blade or contiguous multi-blade designs with large surface areas in continuous contact with the excavated materials. Although the contiguous blade design ensures that the earth materials are smoothly graded along the surface of the earth, a contiguous blade is not necessary for performing rough excavating and grading of earth materials. Many applications such as initial road bed construction, terrace construction on farmland, waterway construction, ditching, diking and open pit mining do not require a smooth finish to the earth materials after each pass of the earth moving machine. For these types of rough excavating and grading applications, the efficiency of the earth moving machine is improved by using discrete disk blades for excavating ribbons of earth materials and discharging these materials laterally with high momentum. Frictional forces associated with shifting earth materials along a contiguous blade are significantly reduced with discrete disk blades, particularly if the earth moving machine has sufficient horsepower to maintain a speed of at least five miles per hour. Only the last disk blade of a plurality of disk grading units is constrained to grading materials in a manner analogous to conventional earth moving blades.
My invention describes a rough excavating and grading attachment using discrete disk blades laterally spaced along a beam which can be attached to conventional dozer C frames such as disclosed in U.S. Pat. No. 4,167,979 to Freese and Wheeler, attached to frame assemblies for power machines such as disclosed in U.S. Pat. No. 4,306,625 to Davis, attached to agricultural dozer frames such as disclosed in U.S. Pat. No. 4,304,305 to Bartel or attached to other types of tractive pushing frames. The U.S. Pat. No. 4,597,452 issued to Tapphorn R.M. and Tapphorn D.E., is exemplary of the class of discrete disk blade graders, however, the disk grading terrace plow cited in the referenced invention is restricted to towing in its application and claims.